For the purpose of preventing pollution induced flashover on transmission line insulators

it is necessary to understand conductivity variation of insulator surface contamination during rain’s flushing insulator surface pollution layer

and to investigate dynamic accumulation of the contamination. In this paper

artificial rainfall is simulated to flush the contamination on insulator surface with different pollution degree

and to flush the insulator surface during dynamic accumulation of contamination. The variation law of conductivity of pollution layer on insulator surface is thus achieved. It is shown that the contamination conductivity reaches its maximum as the contamination layer gets soakage saturation

and then becomes smaller gradually with continuous rain rushing until a clean surface is obtained.